Psychology is the science of the mind. The human mind is the most complex machine on Earth. It is the source of all thought and behaviour.

How do psychologists study the mind?

But how can we study something as complex and mysterious as the mind? Even if we were to split open the skull of a willing volunteer and have a look inside, we would only see the gloopy grey matter of the brain. We cannot see someone thinking. Nor can we observe their emotions, or memories, or perceptions and dreams. So how do psychologists go about studying the mind?

In fact, psychologists adopt a similar approach to scientists in other fields. Nuclear physicists interested in the structure of atoms cannot observe protons, electrons and neutrons directly. Instead, they predict how these elements should behave and devise experiments to confirm or refute their expectations.

Human behaviour: the raw data of psychology

In a similar way, psychologists use human behaviour as a clue to the workings of the mind. Although we cannot observe the mind directly, everything we do, think, feel and say is determined by the functioning of the mind. So psychologists take human behaviour as the raw data for testing their theories about how the mind works.

Since the German psychologist Wilhelm Wundt (1832-1920) opened the first experimental psychology lab in Leipzig in 1879, we have learned an enormous amount about the relationship between brain, mind and behaviour.

Psychology and other disciplines

Psychology lies at the intersection of many other different disciplines, including biology, medicine, linguistics, philosophy, anthropology, sociology, and artificial intelligence (AI).

For example, neuropsychology is allied with biology, since the aim is to map different areas of the brain and explain how each underpins different brain functions like memory or language. Other branches of psychology are more closely connected with medicine. Health psychologists help people manage disease and pain. Similarly, clinical psychologists help alleviate the suffering caused by mental disorders.

Branches of psychology

Any attempt to explain why humans think and behave in the way that they do will inevitably be linked to one or another branch of psychology. The different disciplines of psychology are extremely wide-ranging. They include:

Clinical psychology

Cognitive psychology: memory

Cognitive psychology: intelligence

Developmental psychology

Evolutionary psychology

Forensic psychology

Health psychology

Neuropsychology

Occupational psychology

Social psychology

You can learn more about these disciplines by selecting from the list of links on the right hand side of the page.

What all these different approaches to psychology have in common is a desire to explain the behaviour of individuals based on the workings of the mind. And in every area, psychologists apply scientific methodology. They formulate theories, test hypotheses through observation and experiment, and analyse the findings with statistical techniques that help them identify important findings.